1. Field of the Invention
This invention is particularly directed to an improved fluidized bed combustion apparatus and to a method for rendering the operation of such apparatus economical.
2. Description of the Prior Art
It is known that fluidized bed combustion of coal is the subject of current study by many organizations manufacturing and supplying to the industry variations in the type of fluidized bed combustion apparatus.
Papers have been authored on this subject, such as one by Taylor Moore under the title "Achieving the Promise of FBC", appearing in EPRI Journal, January/February 1985 (pages 6-15), and the Special Report that appeared in Power, February 1985, entitled "Fluidized-Bed Boilers Achieve Commercial Status Worldwide", by Schweiger, Editor-in-Chief (pages S-1 to S-16, and the article by Leon Green Jr. which appeared in Coal Mining, November 1985, entitled "They're Off" in the circulating FBC handicap.
In the prior patent art there appeared a suggestion of supplying pulverized fuel to a boiler in the Dickey U.S. Pat. No. 2,172,317 issued Sept. 5, 1939. The concept of producing two products, fines and coarse, from coal processing apparatus has been disclosed by Williams in U.S. Pat. No. 4,461,428 of July 24, 1984.
It is recognized that the problem in fluid bed combustion chambers at the present time is how to burn different types of wet coal without carbon loss through escape of coal fines and without plugging the feed system with the wet fines.